Power and heaters

1. The problem statement, all variables and given/known data
A heater rated at 2000W operating at 250V is used on a supple of 230V. if the resistance of the heater will not be affected by temp, what is the power absorbed by the heater?

2. Relevant equations
i think that the only equation to use will be P=V^2/R

3. The attempt at a solution
because the resistance of the heater is its internal property, i would first compute for the resistance from: R=(230^2)/2000. afterwhich, i would compute the power absorbed by the heater through: V=250-230=20 -> P = (20^2)/R which will be computed from the previous equation. is this right?